Flexibility, a key priority for the industry
Managing Director – Equipment Department
Mecapack PROPLAST Group
Flexibility and OEE (Overall Equipment Effectiveness) have become keywords to industrial production.
Today optimizing downtime when production formats are changed is a priority. The solution lies in machines that are more and more innovative and flexible.
The flexibility and just-in-time requirements in consumer retailing has never been greater. In some cases, it may give rise industrials overinvesting and overproducing by approximately 30%; a consequence I have witnessed to varying extents while meeting several manufacturers in the food and beverage industry. We have thus considered how to assist customers in being more flexible; quite simply through machinery that gives flexibility.
Shortening format changeover times
We have therefore focused on the time-consuming element in the packaging process: format changeover. And we have tried to reduce it to a minimum so that the customer’s OEE (Overall Equipment Effectiveness) is increased.
As an interesting side-effect, the concepts of productivity, flexibility and OEE have led to improving the conditions of use of the machines (more ergonomic and easier to use).
All the studies have been carried out to minimize handling in an attempt to save time and, by extension, to improve safety; both on our tray sealing and thermoforming machines.
Innovating in sealing machines with the carrousel and line separation
The sealing machine is formed of upper tooling and lower tooling that corresponds to the format of the tray. Before, in order to change tooling, it was necessary either to lift weights of approximately 20 to 25 kilos, or to use a trolley with chains that removed the tooling, with the risk of tying it up inappropriately and dropping… Now, the machinery is equipped with a rotary carrousel system onto which 4 heavy upper tools are attached. All that is required from the operator is change a four-kilo sealing mask on the lower part of the machine. Depending on the choice of the frame, the machine automatically recognizes the format. The carrousel will then index itself on the appropriate upper part. Once the tray sealing frame is changed, the rest takes place on the screen without any handling.
With the carrousel, we can change a tooling format on tray sealing machines in 2 to 3 minutes, compared to the standard 15 to 20 minutes. The actual production time is therefore significantly increased. This carrousel technology is particularly recommended for small and medium rates.
On the other hand, for high rates, it is better to focus on the concept of “separate lines for different formats”. The carrousel system cannot be applied to large capacity machines, since the installed weight is too high. We have thus circumvented the problem by designing larger machines and by installing the tooling permanently on the machine. Each tray sealer is then dedicated to two formats (with two distinct lines) in order to eliminate tooling changeover. The upstream flow will simply be directed either to format A or to format B. The transition takes place with no time wasted.
Improving flexibility on thermoforming machines
The same problem applies to thermoforming. However, in this case, three elements have to be altered when formats are changed: on-line manufacturing of tray; sealing tooling and cutting. Until now, the change could take between 40 minutes and 1 hour. Now, thanks to flexibility-focused design, we are down to 15 to 17 minutes.
In order to get these results, we started by carrying out a SMED study. We listed and broke down all the production tasks and stages. We tried to reduce downtimes by working on a more straightforward procedure. From a technological standpoint, we have developed auto-locking handles that enable, for example, to lift upper tooling in only 5 seconds, compared with the usual 5 to 6 minutes.
We have also developed automatic depth adjustment systems; automatic sealing plate removal systems that eliminate the risk of being burned; and barrel cutting systems. It results that manual operations are reduced to their simplest form.
In the future we are going to bring format changeover to an even higher level, since it relates to the very heart of the machine. It is its very essence.
More about Pierre-Yves Berthe
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